**1. Introduction**

Low levels of poverty due to failure of growth in Gross Domestic Product (GDP) per capita has been observed in sub-Saharan Africa where the average real per capita income in year 2010 was 688 USD as compared to 1717 USD in other developing countries of the world [1]. Agriculture is a major contributor to GDP in Africa (up to 32%). Nevertheless, the sector is characterized by low productivity. It is important to increase agricultural productivity in Africa to ensure poverty reduction [1]. In addition to poverty, inhabitants of most cities in sub-Saharan Africa are experiencing micronutrient deficiencies. For instance, over 200 million and 1.6 billion suffer from Vitamin A and iron deficiencies respectively [2, 3]. In the same vein, it is expected that the populations in urban cities across sub-Sahara Africa will increase rapidly due to rural–urban migration and natural population increase [4]. A projection of 20.2% increase is expected by 2050 [5] which will place more burdens on the currently available food, fruits and vegetables in cities across the region. Other challenges posed by the rapid growth in these urban areas include food insecurity and unemployment [6]. Urban agriculture/horticulture is a veritable solution to these identified problems in the urban areas of sub-Sahara Africa.

There are various definitions of the term "urban"—an urban area can be determined based on a number of factors; for instance, population size, density, administrative function and other indicators such as infrastructure, facilities, employment [7].

Urbanization is the increase in number of people living in the cities caused by migration, commercialization, industrial growth and social factors (presence of educational facilities, better standard of living) [8].

Urban Agriculture (UA) can be defined as "an industry within (intra-urban) or on the fringe (peri-urban) of a town, city or metropolis which grows, raises, processes and distributes a diversity of food and nonfood products using largely human and material resources, products and services found in and around that urban area and in turn supplying human and material resources, products and services largely to that urban area" [9].

Fruits and vegetables form an essential part of horticultural crops rich in fiber, minerals and bioactive compounds. Consumption of fruits and vegetables is necessary to ensure healthy diets for balanced nutrition. They are consumed alongside staple foods and prevent diseases as a result of deficiencies across the population. Diets of most of urban dwellers are deficient in micronutrients such as vitamin A, iron, iodine, zinc [10].

The most widespread form of urban agriculture involves horticultural crops [11]. From their own viewpoint, Dimas et al. [12] defined urban agriculture as the production of fruits, vegetables and food within the urban environment for household consumption and sale. Considering the aforementioned, it can be inferred that urban horticulture is urban agriculture which has to do with production of horticultural crops—fruits, vegetables, spices, and ornamental and other medicinal crops. Thus, in this chapter, urban horticulture is urban farming with horticultural crops in focus.
